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pathname

pathname Function

Syntax:

pathname pathspec → pathname

Arguments and Values:

pathspec—a pathname designator .

pathname—a pathname.

Description:

Returns the pathname denoted by pathspec.

pathname

If the pathspec designator is a stream, the stream can be either open or closed; in both cases, the pathname returned corresponds to the filename used to open the file. pathname returns the same pathname for a file stream after it is closed as it did when it was open.

If the pathspec designator is a file stream created by opening a logical pathname, a logical pathname is returned.

Examples:

;; There is a great degree of variability permitted here. The next 
;; several examples are intended to illustrate just a few of the many 
;; possibilities. Whether the name is canonicalized to a particular 
;; case (either upper or lower) depends on both the file system and the 
;; implementation since two different implementations using the same 
;; file system might differ on many issues. How information is stored 
;; internally (and possibly presented in #S notation) might vary, 
;; possibly requiring ‘accessors’ such as PATHNAME-NAME to perform case 
;; conversion upon access. The format of a namestring is dependent both 
;; on the file system and the implementation since, for example, one 
;; implementation might include the host name in a namestring, and 
;; another might not. #S notation would generally only be used in a 
;; situation where no appropriate namestring could be constructed for use 
;; with #P. 
(setq p1 (pathname "test")) 
→ #P"CHOCOLATE:TEST" ; with case canonicalization (e.g., VMS) 
<i><sup>or</sup>→</i> #P"VANILLA:test" ; without case canonicalization (e.g., Unix) 
<i><sup>or</sup>→</i> #P"test" 
<i><sup>or</sup>→</i> #S(PATHNAME :HOST "STRAWBERRY" :NAME "TEST") 
<i><sup>or</sup>→</i> #S(PATHNAME :HOST "BELGIAN-CHOCOLATE" :NAME "test") 
(setq p2 (pathname "test")) 
→ #P"CHOCOLATE:TEST" 
<i><sup>or</sup>→</i> #P"VANILLA:test" 
<i><sup>or</sup>→</i> #P"test" 
<i><sup>or</sup>→</i> #S(PATHNAME :HOST "STRAWBERRY" :NAME "TEST") 
<i><sup>or</sup>→</i> #S(PATHNAME :HOST "BELGIAN-CHOCOLATE" :NAME "test") 
(pathnamep p1) → true 
(eq p1 (pathname p1)) → true 
(eq p1 p2) 
→ true 
<i><sup>or</sup>→ false</i> 
(with-open-file (stream "test" :direction :output) 
  (pathname stream)) 
→ #P"ORANGE-CHOCOLATE:>Gus>test.lisp.newest"

See Also:

pathname, logical-pathname, Section 20.1 (File System Concepts), Section 19.1.2 (Pathnames as

Filenames)

Expanded Reference: pathname​

Converting a string to a pathname​

The pathname function converts a pathname designator (a string, stream, or pathname) into a pathname object.

(pathname "foo.lisp")
=> #P"foo.lisp"

(pathnamep (pathname "foo.lisp"))
=> T

A pathname passed through is returned as-is​

When the argument is already a pathname, pathname returns it unchanged (it is identity on pathnames).

(let ((p #P"/tmp/test.txt"))
  (eq p (pathname p)))
=> T

Converting from a file stream​

When given a stream associated with a file, pathname returns the pathname used to open that file. This works on both open and closed streams.

(with-open-file (s "/tmp/cl-test-pathname.txt"
                   :direction :output
                   :if-exists :supersede)
  (pathname s))
=> #P"/tmp/cl-test-pathname.txt"

Extracting components after conversion​

A common pattern is to convert a string to a pathname and then access its components.

(let ((p (pathname "/home/user/document.txt")))
  (values (pathname-name p)
          (pathname-type p)))
=> "document"
=> "txt"